Improvements in Apparatus for Electrical Lighting.
Year: 1893

page_text: Date of Application, 17th Mar., 1893-Accepted, 27th May, 1893
COMPLETE SPECIFICATION.
Improvements in Apparatus for Electrical Lighting.
I, PAUL SCHARF, of I Wipplingerstrasse 38, Vienna, Austria, Engineer, 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:--
This invention chates to apparatus for electric lighting installations and has for
its object to greatly increase the duration of the electric glowlamps operating with
small consumption of current so that these lamps (which alone render possible the
production of a certain amount of light at the same cost as when produced by
other means, such as by improved gas burners) can be used with particular
advantage for lighting purposes.
As is well known, the duration of all lamps with small consumption of current,
is a short one, it being the shorter, the more economically they operate, because
these lamps require to have a comparatively very thin carbon filament, which on
this account, and on account of the small thickness of the harder and more resisting
layer of carbon deposited thereon, is very subject to disintegration in the high
temperatures to which the filament is subjected, corresponding to the small amount
of current consumed. In consequence of this such lamps only retain their original
normal illuminating power for a short time.
To this is added the circumstance that the long and thin carbon filaments readily
chem defective places, which, not being recognisable during the manufacture, often
terminate the already short duration of the lamp, very shortly after starting.
All attempts to improve the carbon filaments in this respect have proved
fruitless.
It is however nevertheless possible to considerably increase the duration of the
activity of such lamps, by the employment of several filaments in one and the same
lamp, which are consecutively put into action.
But the employment of several filaments in the lamp does not do away with the
before mentioned defect of rapid destruction of the individual filaments; further-
more, there has to be considered the circumstance that the tension of the current
at the places of consumption is never constant, but is as a rule subject to fluctuations
which, even when small, have considerable influence upon the lighting power, in
particular of low-Watt power lamps, and rapidly destroy them. On the other
hand, it is a fact shewn by experience that lamps of a high candle power more
readily resist the action of a strong current, that is to say they can burn with less
watts per light unit, because their thick carbon loop po-sesses a greater degree of
durability, and the carbon layer deposited thereon does not so easily disintegrate.
It would therefore be advantageous to construct low-Watt lamps also with thick
carbon loops, but this is only possible if the lamps are arranged for low tension
currents. This can only be done by arranging the lamps in groups in series in a
circuit with current of ordinary tension.
The tension most advantageous for the size of the carbon filaments is one of
from 25 to 30 volts, from which groups of from two or four lamps each, in series,
result, according as the usual tensions of from 50 to 65 volts or of 100 to 120 volts
are employed.
The arrangement of apparatus for electric light installations which forms the
subject of the present invention and which is applicable with advantage in cases
where there is a large daily production of light, comprises as its main feature the
above described arrangement in series of groups of glow lamps, each having several
filaments, by which means alone low-Watt power lamp can be rendered of
comparatively long duration.

page_text: The lamps employed in such installations, have special constructions with
reference to the relative arrangement and fixing of the carbon filaments, and they
are provided with switch devices which, on the destruction of one of the carbon
loops of the lamp, automatically effect the putting in circuit of the next carbon
loop, no matter whether the lamp is operating alone, or in combination with any
number of other lamps arranged in series.
These switches can be so constructed that at each compling up and uncoupling
of the main current, the carbon filament put in action is changed, so that a uniformi
wear of the carbon filaments of the lamp will result, also, irrespective of the
number of lamps that are arranged in series,
On the accompanying drawings
Figures 1 to 6 shew various modes of arranging and fixing the carbon filaments.
Figure 7 shows the diagram of a switch apparatus for lamps with several
filaments.
Figures 8, 9 and 10 shew a side view, plan and horizontal section of a switch
apparatus for lamps with two filaments.
Figures 11 and 12 are two vertical sections at right angles to each other.
Fig. 13 a plan and Figs. 14 and 15 two horizontal sectional views looking
respectively upwards and downwards from line. Fig. 11; these several views
shew the construction of a switch apparatus by means of which, on the burning
through of a filament, the next following filament of the lump is automatically put
in circuit.
Fig. 16 lows a vertical section. Fig. 17 a plan and Fig. 18 a horizontal section
of another construction by means of which the automatic putting in circuit of the
consecutive carbon filaments is effected both on the burning through of a filament,
and on putting the lamps of a group into and out of circuit.
In order to fix the carbon filaments of such low-Watt power lamps with two or
more filaments, in their relative positions, circular or star shaped dises A of
insulating material, such as glass, steatite, gypsum, are employed, as shown at
Fig. 1 to 3, in which are fixed short thick pieces of bored wire or metal tubes B,
the number of which is double that of the carbon loops. Into these tubes are
fitted from below the wire leads C, while into the upper ends are fitted wires D
that are connected in the known manner by a carbon deposit or cement to the
carbon filaments, these wires being secured by an easily fusible solder.
The fixing of these wires D can also be effected by slitting the upper ends of
the tubes Band forming them with an external screw thread on which is screwed
a small nut B which is screwed down after introducing the wire D as shewn
at Fig. 2.
When using a glass star, the wire leads (fixed in the tubes B can be secured to
the arms of the star by melting with a blow pipe as at Fig. 3.
The metallic connection between the wire leads (nelted into the glass and the
metal wires 1) carrying the carbon filaments can also be so effected that the wire
leads are formed helically or with a socket at their upper end (1, as shown at
Fig. 4, into which the wires D are inserted and secured by a hard solder.
The fixing of the carbon loops in their relative position is effected as follows.
A glass rod S Fig. 5, which is melted together with the lower cup shaped part
of the glow lanp, carries at its upper end a number of platinum wires E E that
are melted in so as to be insulated from each other, and are bent into loop or hook
shape at their upper ends, through each of which a carbon filament is passed. In
place of the glass rod may be used a wire T Fig. 6, which carries a glass head K
at its upper end.
The switch device for the carbon filaments secured in the above described
manner, whereby on the burning through of one filament the next filament is at
once automatically put in circuit, consists of a number of electro magucts or
solenoids (when using alternating currents) which by means of their armatures or
cores are connected with the wire leads, with the separate filaments of the lamp,
and with each other, as shewn at Fig. 7. The main current passes through the

page_text: windings of an electro magnet (or solenoid) m² and from thence into the filament ¿¹
of the glow lamp.
By this means the armature a' is attracted and interrupts the electric connection
with the following electro magnets and filament of the same lamp in connection
therewith. If the filament is burnt through, the current is interrupted in the
coils of m', and the armature, being made to fall by its own weight or by a spring,
makes contact with the contact plate which is imbedded in the insulating plate b.
The main current now flows through the windings of the second magnet m² to the
filament, while at the same time the armature is attracted, thereby inter-
rupting the connection with the next electro magnet m³ and its filament . On
the burning through of the second, third &c., filaments, the same operation is
repeated in the switch apparatus so that
are always put in
circuit.
Dew
1 ts
With this arrangement of switch apparatus consequently several lamps arranged
in series are in so far independent of each other, that on the burning through of a
filament of one lamp the other lamps are only extinguished during the exceedingly
short time which is required for switching a new lilament of the said lamp into
circuit, this time being so short as to be only appreciable to the eye as a slight
fluctuation of the light.
When however, the last filament has become burnt through in a lamp the other
lamps cannot of course continue to act, even when they have still perfect filaments,
and it would then he a difficult matter to find out the particular lamp having no
perfect filaments left, in order to replace it by a nesë 6012. In order to avoid this
difficulty, the switch apparatus is so arranged that as each lamp has one filament
more than there are electro magnets or solenoids, as shewn on the diagram, this
Inst Glument is replaced by a wire or similar resistance, which is of such an extent
as to equal the resistance of the incandent filaments. This resistance is fixed
permanently in the switch apparatus and is arranged exactly as a lamp filament,
so that after the burning through of the last filament (in the example shewn
filament the resistance is put in circuit. The other lamps will consequently
continue to burn so that the extinguished lamp can be readily seen and changed.
The construction of the switch apparatus for lamps with two filaments is shown
at Figs. 8 to 10. In this arrangement the two magnet spools m m
through which
the lamp current passes, their armature a and contact are arranged within the
fitting of the lamp.
The main contact / actuated by the handlen serves for closing or breaking the
lamp circuit. The lamp current passes into the lamp fitting at the screw terminal |
where it becomes divided, the one branch passing through the winding of the
magnet pools mm into the contact stud 1 and from there through the first carbon
filament which is thus heated to incandescence. From the carbon filament the
current passes to the common contact stud 3 and from here, in case the main
contact actuated by handle a establishes the connection between 3 and the pin s,
the current passes through the terminal screw II back into the main circuit.
On the current passing through the magnet windings, the iron cores of the
spools mm are rendered magnetic, whereby the armature a fixed to the spring/
and which is always pressed by the spring against the contact c is raised up from
later. By the raising up of the armature the ether branch of the lamp current is
interrupted which passes from the terminal screw through the spring to the
an nature. It now by the burning through of the first carbon loop the current
passing through the contact stund 1 through this carbon filament and the common
contact stud 3 is interrupted, the armature a will be removed from the electro
magnet by the spring and pressed on to the contact c, whereby the lamp current
will pass from the latter to the supports and thence to the contact studs 2,
thereby bringing the second carbon filament in circuit so as to be heated to
incandescence. Thence the current passes from the common contact 3 back into
the main circuit.

page_text: In this case, as also in the previous one, the main contact / can close or open
the lamp circuit by the rotation of the handle a whereby the connection between 3
and is either made or interrupted. If on the burning through of a filament the
following one is to be automatically put in circuit without interrupting the action
of the other lamps arranged in circuit for a longer time than the momentary
putting in circuit, the switch apparatus is constructed as shown at Figures 11
to 15.
r
f.
The switch apparatus consists in this case of three magnet spools fixed on an
insulating plate q. Two of these spools m² and are wound with thin wire and
form an electro magnet contained in a shunt circuit fixed on a common pole plate e
The third spool has a lamp current passing through it and is fixed by means of
the angular support upon the base plate q. On the latter there is also fixed a
weak blade spring by means of a screw o in an insulated manner, the other end
of which spring lies underneath the pole of the spool and has rivetted to it an
iron plate that is attracted as an armature by the iron core of the spoul r on the
passage of the current, but which at other times is pressed by the spring /' on to
the plate
The upper insulating plate carries on the outer side 4 or 5 spring
contact studs 1, 2, 3, 4 and 5 of which the middle one forms the common pole; the
others pass through the plate and project on the inner side. On the inner side
of the plate q' is fitted a central axis to which are connected rotatably the flat
armature which vibrates between the poles pp of the shunt magnet, and a small
toothel dise. The armature carries a tooth or pawl which is maintained in
gear with the teeth of the dise s by means of a small spring so that it can turn the
dise. The latter carries in addition a sliding intact d which slides against the
underside of the plate and comes in contact with the ends of the contact
studs 1, 2, 3 and 4. From the nut screwed on to the axis an insulated wire passes
to the screw terminal II. The armature a is removed from the poles pp of the
shunt magnet by means of the helical spring which is attached to the pin i. In
addition there is fixed to the armature a long flat spring which passes through a
-Jot in the upper plate y' and at the outermost position of the armature comes in
contact with the setting screw y whereby the Shunt circuit will be closed. The
main current passes at the terminal screw into the switch apparatus where it
divides into the lamp current and the shunt current. The first passes into the
winding of the spool e then through a wire that passes through a hole in the plate gl
to the spring middle contact 3.
The
If now the sliding contact touches one of the contacts on the inner surface of the
plate 7', the current can pass from the middle contact through one of the carbon
loops to its second pole and through the sliding contact into the axis t to the
nut and through the insulated wire to the terminal screw II of the switch
apparatus. In this case the lamp is in action. When however, the carbon filament
in action is burnt through, or if on the closing of the main circuit the sliding
contact d should not be in contact with any of the insulated contacts 1, 2, 3 or 4
then as the main current is interrupted the spool remains unmagnetised and the
small armature makes contact with the pole plate. The current then passes
through the shunt circuit from the terminal screw into the windings of the
spool m' the ends of which are connected metallically with the pole plate e.
shunt current therefore passes through this plate and the spring to the screw o
to which the windings of the spool m² are connected. It flows through these
windings and passes through an insulated wire passing through plate to the
setting screw y As this still touches the blade spring the current passes from
the spring into the armature & and thence through the nut and wire to the
terminal screw II, The shunt circuit is therefore entirely closed, the iron cores
of the spools m' m² become magnetie, and the armature a is attracted by the
poles pp, whereby the pawl comes in gear with the next tooth of the disc
By the movement of the armature à out of its first position, the shunt enrrent
will be again interrupted at and y, the spools m' m² lose their magnetism again,

page_text: and the helical spring draws the armature back into its original position, while
the toothed disc is thereby at the same time moved a distance of one tooth. The
entire operation is similar to that of a "Neef" hammer and is repeated until the
sliding contact is caused by its motion imparted by the disc 2 to slide on
the plate till it closes the main current and thus puts one of the lamp
filaments in action. This arrangement fulfils entirely the desired object, as a
sufficient current only then passes through the shunt circuit when the main circuit
is interrupted and consequently only in this case the shifting of the sliding con-
tact will be effected. If the main circuit is closed, the device does not operate.
Also, in the case of several lamps connected in series, on the burning through
of a filament of one of the lamps, only the shunt device of this particular lamp
will be actuated in the described manner until a new filament is put in circuit.
During this exceedingly short interval of time required for the putting in circuit
of the filament, no doubt all the lamps in series will be extinguished, but the
shifting of the sliding contacts will not occur in these as the shunt current
will, to by far the largest extent, pass through the filaments of those lamps which
are still in circuit, as the resistance of these will be considerably less than that of
the shunt windings.
With this correct function of the above described switch apparatus there will
however still occur a loss of current owing to the fact that during the burning of
the lamps some current will always pass through the shunt circuit. In order to
prevent this loss of current or to reduce it as much as possible the spool with its
small armature connected to spring is provided, the armature on the closing of
the main circuit being attracted by the iron core of the spool, whereby the shunt
circuit will be broken between the spools in and m³. As the spring can be very
weak, very few windings on the spool will be sufficient and the loss of current in
the latter is thus reduced to a minimum, certainly much less than with a continually
closed shunt circuit.
When, in an electric light installation, the above described switch apparatus is
required, in addition to the automatic putting in circuit of a new filament on the
burning through of another, to fulfil the condition that on each putting in and out of
circuit of the lamps of a group a different filament shall be brought into action in
each of these lamps, the arrangement shewn in Figs. 16 to 18 can be used with
advantage. In this case the switch apparatus consists of the main circuit
spools M M and the shunt circuit spools mm². From M2 a wire passes to the
middle contact after passing through the insulating plate q'; from the winding of
the shunt spool m² another insulated wire passes in a similar manner to the setting
screw y and from this through the blade spring g to the armature a which is
connected by the nut and an insulated wire with the terminal screw II. The
four spools are situated on a common star shaped pole plate e and are fixed with
the latter upon the insulating base plate y. The double armature a made of one
piece is also star shaped and is in contact simultaneously with the four poles p p P P
of the two electromagnets. A pin s fixed to the armature passes like the blade
spring through a corresponding slot in a plate 7 and from above the same a
point of contact for a helical spring fixed to the stud which continuously tends
to remove the armature a from the poles. The armature a is fitted rotatably upon
an axis which is screwed in an insulated manner into the plate g', which axis t
carries the toothed disc s with sliding contact d. The armature also has fixed to
it a pawl which is in gear with the tooth of the discs. The spring contacts 1 to 4
passing through the plate q' are made somewhat uarrower on the underside of
this plate than the sliding contact d, also the pitch of the toothed discs is so
proportioned that the movement of this disc and of the sliding contact & caused by
a simple motion of the armature a shall be exactly as great as, or only slightly
greater than the width of the sliding contact. By this means it is ensured that
when the latter is situated upon one of these four contacts it will on the following
motion of the armature a away from the poles, leave this contact with certainty.
=

page_text: When the main eirenit is closed, the sliding contact d will never stand on a contact
and therefore the current in the lamp itself will be interrupted, but as the armature a
is removed from the magnet by the spring and stands in its outermost position,
the shunt circuit is closed. The shunt current then passes from the terminal
screw through the spools m² m² to the setting crew, through the blade spring
to the armature a and from the axis and nut and an insulated wire to the
terminal screw 11. The spools are thus rendered magnetic, attracting the
armature and consequently, the blade spring again leaves the setting screw,
the shunt circuit is again interrupted, the armature a is removed from the magnet
and thereby shifts the disc 2 one tooth. This operation is repeated until the sliding
contact d makes contact with one of the four contacts. The main circuit is then
closed, the spools M M are suddenly rendered magnetic and attract the second
arm of the amature so that this can no longer be drawn back by the spring h, and
consequently a further shifting of the dise on the sliding contact it is prevented. If
now the main circuit is interrupted the armature a is removed from the magnet the
sliding contact leaves the contact on which it was situated, and on the following
closing of the main cirenit the following contact must be closed with certainty,
whereby also a different carbon filament will be brought into action. The same
operation of course takes place on the burning through of a filament of one of the
lamps.
Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed. I declare that what I
claim is
1. In an electric light installation, the arrangement of groups of glow lamps
connected in series, each having two or more carbon filaments, and so arranged that
on the burning through of one of the filaments of the lamp, and, if required, also
on the putting in and out of circuit of the lamps of a group, the said filaments are
consecutively put in action, substantially as described.
2. Constructing glow lamps with two or more filaments, which are held in the
required relative positions by having their supporting wires D carried in tubes B
which serve for the attachment of the wire lead- C, and which are secured to an
insulating dise or star shaped body A. Figs. 1, 2 and 3, or which filaments have
their supporting wires D secured by soldering in sockets (of the wire leads Cas
at Fig. 4, substantially as described.
3. Constructing glow lamps with two or more filaments which are held in the
requisite relative position, by being passed through platinum loops secured in an
insulated manner in a holder S or T. substantially as described with reference to
Fig. 5 and 6,
4. A switch apparatus for glow lamps having two or more filaments, consisting
of one or more electro magnets or solenoids mor m² në
which are so con-
nected to the eirenit leads, to the carbon filaments and to each other by means of their
armatures or iron cores or a a², that on the burning through of a filament,
the next filament of the lamp is automatically put in circuit, substantially as
described.
5. A switch apparatus for glow lamps having two or more filaments consisting
firstly of an electro magnet m² m² in a shunt circuit, having a vibrating armature a
whose tooth or pawl is made, on the exciting of the electro-magnets, to gear with
a toothed discs carrying the sliding contact d for the putting in circuit of the
carbon filaments, while on the demagnetising of the electro magnet the said tooth j
shifts the toothed disc, and secondly, of an electromagnet with armature r, for the
purpose of avoiding losses of current in the shunt circuit, substantially as described
with reference to Figs. 11 to 15.
?'
6. A switch apparatus for glow lamps with two or more filaments for automatically
putting in circuit a new filament both on the burning through of the previous
filament and also at each putting in and out of circuit of the lamps, consisting of

page_text: the main circuit spools M' M³ and the shunt circuit spools m² m² with the double
armature a, arranged and operating substantially as described with reference to
Figs. 16 to 18.
ABEL & IMRAY,
Agents for the Applicant.