IMPROVEMENTS IN LIGHTING BY ELECTRICITY
Year: 1879

page_text: PROVISIONAL SPECIFICATION left by Alexander Melville Clark at the
Office of the Commissioners of Patents on the 16th May 1879. A communi-
cation from abroad by Nicolas Emile Reynier, of Paris, France.
«
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent.
"IMPROVEMENTS IN LIGHTING BY ELECTRICITY." [A communi-
cation from abroad by Nicolas Einile Reynier, of Paris, France.]
The chief objection to the electric light is its liability to be partially or totally
extinguished from various causes. The extinction of the light by the complete
consumption of the carbons or electrodes is easily provided against by switching
the current through another pair of carbons before the first are in the ordinary
course quite consumed. This is generally done by an attendant, but it may also be
done by automatic means. Arrangements of this kind are however insufficient in
practice, as the light is not only liable to be extinguished when the carbons are
quite consumed, but at any moment an accident to which all known lamps or regu-
lators are subject. This accident is especially inconvenient when the extinction of
one of a number of lights placed on the same circuit involves the extinction of all.
It is therefore indispensable in this case, and very useful in all others, to provide
against the extinction of the light, either from an accidental cause, or from neglect
to renew the electrodes.
The purpose of the present Invention is to enable this object to be automatically
accomplished. To this end a number of change lamps are combined for the pro-
duction of each single electric light, so that if the first lamp is extinguished from
any cause whatever a second one is immediately substituted for the first, and a
third for the second, a fourth for the third, and so on. The last lamp of the series
may be replaced by an equivalent resistance, so that the whole of the lamps being
out of working order will cause the extinction of this individual light only without
involving the extinction or modifying the intensity of the other lights on the same
circuit. Moreover it is only necessary to again put the lamps into working order
to cause them to relight and successively substitute themselves the one for the other
in the desired order.
The switching of the current from the one to the other is effected automatically
at the proper moment, as hereafter described.
c

page_text: The principle of the apparatus of this Invention consists in placing the change
lamps each in a derivation of the principal current, and in inserting in the deriva-
tion appropriated to each of these lamps, except the last one, electro magnets or
solenoids, which open the derivations of the succeeding lamps when they are
magnetized, and close them when they are demagnetized. These electro magnets
or solenoids are distinct from those which may form part of the mechanism of the
lamps.
In order that the principle may be more readily understood I will first explain it
with reference to diagrams (sec accompanying Drawings).
In Figure 1 P and N are the wires from the positive and negative poles of an
electromotor E, by which a single light is established by means of one of three
lamps L', L², L³. These three lamps are placed in derivations p¹, n¹, p², n², p³, n³,
of the circuit P, N. An electro magnet or solenoid AL¹ is interposed between n¹, n²,
and another between n² and n³. When the electro magnet M¹ is active the con-
nection of n with N is broken at c', and is restored when said electro magnet
becomes inactive, and similarly the connection of n³ with M. is broken and restored
at c by the magnetization and demagnetization of M². By this arrangement only
one of the three derived circuits can be closed at one time; thus, when lamp L'
is working, the current which produces the light must traverse and excite the
magnets M1, M2, thus breaking at c', c², the circuits passing through lamps L², L³.
When the circuit through L is broken, either by the consumption of its carbons or
from any accidental cause, M' and M2 are demagnetized, and allow the connection
at c¹, c², to be restored; but the magnet M² being at once remagnetized by the
current passing through lamp L2 immediately breaks the connection at c², which is
not closed again until by the breaking of the circuit through L³ it becomes necessary
to establish the circuit through L³.
Figure 2 represents an electro motor supplying two lights arranged in derivation,
each comprising three change lamps. The two groups of lamps act individually in
the same way as the single group in Figure 1. The same letters of reference are
applied to the same parts in both, those of the second group of lamps being
accented.
Figure represents an electro-motor supplying three lights, arranged in tension,
and comprising three change lamps, the three groups of lamps acting individually
like the single group of Figure 1. The same letters of reference are applied to the
same parts, as before, those of the second group being accented once, and those of
the third group twice.
Having thus explained the principle of the Invention, I will proceed to describe
a practical example of its application.
Figure 4 represents an elevation, and Figure 5 a plan of an apparatus with three
circuits. F, G, H, are three metal posts fixed on an insulating table A; M² is an
electro magnet, whose coils are connected at one end to F, and the other to G; and
M is another electro magnet having its coils similarly connected to G and H. The
wire N from the electro motor is connected to F, and the three wires n¹, nº, n³,
respectively attached to H, G, and F, establish the communication of the pole N
with the three derived circuits. The other wire P of the electro motor is connected
to stud B, which is in electric communication with the stud B¹, and with the levers
D and D', carrying the armatures of and actuated by the electro magnets M²
and M¹. The three wires p', p², and p³, which establish the communication of
pole P with the three derived circuits, are attached respectively to the stud B' and
the metal posts C₁, C. When the magnets are demagnetized the levers D¹ and D²
are caused by springs to rest on the posts D1 and C2, and thus put wires p² and p³
in communication with pole P. When, on the other hand, they are magnetized, the
contact of the levers with C₁and is broken.
The operation of the apparatus is as follows:-When the first lamp with which
the wires p' and n¹ are connected is in work, the current which produced the light
traverses the coils of two magnets M1, M2, which, being thus magnetized, attract

page_text: their armatures, and break the contact at C1, C2, so that the circuit p¹, n¹, alone
remains closed. Immediately the first lamp is extinguished from any cause, the
two magnets are demagnetized, and contact is restored at C1, C2, but the current
which traverses the coils of the second lamp, to which are connected the wires p², n²,
inagnetizes the electro magnet M, whereby contact is immediately broken again at
C, and the circuit p², n², alone remains closed.
When the second lamp in turn becomes extinguished, the magnet M² is again
demagnetized, and allows the contact to be again made at C, thus closing the
circuit p³, n³, which passes through the third lamp, or a resistance equivalent to a
lamp. If now the lamps which have become extinguished are put into working
order, they relight and substitute themselves, the one for the other, in the desired
order, for the closing of the first circuit necessarily brings about the breaking of the
two others, and the closing of the second circuit similarly causes the breaking of
the third one. If an electro motor supplies a number of lights at once, arranged in
tension or quantity, a group of several lamps may be provided for each light, each
group being controlled by a distinct apparatus, and the individual action of the
apparatus every time one lamp is substituted for another is sufficiently rapid to
cause but an instantaneous and hardly sensible variation of the other lights in the
circuit.
The construction of the apparatus herein described as an example is only one of
the numerous forms in which its principle may be embodied. The right is there-
fore reserved to modify its construction in any way, and particularly to replace the
electro magnets by solenoids, of which the soft iron cores would break and make
the contacts with or without the intervention of a lever. An example of this
arrangement is represented in the Drawings, in which Figure 6 represents an
elevation, Figure 7 an underside view, and Figure 8 a vertical section on line x-x,
Figure 7. a, hollow base of the solenoid; b, iron core furnished at its lower end
with a stud c of insulating material; d, wire of the solenoid; 1, stud to which the
positive pole of the electro motor is connected; 2, stud to which the positive pole
of the first lamp L' is connected; 3, stud to which the negative pole of the electro
motor is connected; 4, stud to which the negative pole of the first lamp is con-
nected; 5 and 6, studs to which the negative and positive poles of the second lamp
L² are respectively connected. The studs 1 and 6 are electrically connected through
the base frame. The ingress end of the solenoid is attached to the stud 1, and the
egress end to the insulated stud 2. A rigid plate e is fixed beneath the insulated
stud 3, and reaches to the centre of the helix of the solenoid A. The studs 3 and 4
are connected by the plate f, and a flexible plate g, fixed beneath the insulated
stud 5, is pressed against the rigid plate e by the weight of b, which falls when the
solenoid is demagnetized; h is a stationary soft iron core, which by becoming
magnetized assists in lifting b.
The whole being arranged as described, the working is similar to that of the
arrangement before described. The current passes from the electromotor E through
the stud 1 and the solenoid A. and the insulated stud 2 to the first lamp L¹; whence
it returns through the insulated stud 4, the plate f, and the insulated stud 3 to the
electromotor. By the magnetization of the solenoid the core b is raised and is held
up so long as the current passes. As it does not then rest on the plate g, the latter
moves by its own elasticity away from the plate e, so that the current cannot pass
to the second lamp L2. If from any cause the circuit of lamp L' is broken the
solenoid is demagnetized, and b instantly falls on the flexible plate g, and puts it in
contact with plate e, whereupon the circuit is then closed through the second
lamp L. The current then passes from the electro motor through stud 1, thence
through the base frame of the apparatus and the stud 6 to the lamp L³, whence it
returns through stud 5, plate g, e, and stud 3 to the electro motor.
This arrange-
ment of apparatus may be mounted directly on the first lamp L', and in this case
the studs 1 and 3 are dispensed with.

page_text: The right is reserved to separate the various parts here shown as combined in a
single instrument, and to distribute them, say, on the lamps themselves whilst still
retaining their respective functions (which are quite distinct from those performed
by the mechanism belonging to each lamp), and conserving the relative electrical
situations which they must occupy to satisfy the general conditions indicated in 5
the diagrams.