Year: 1886

page_text: Date of Application, 24th Nov., 1886
Complete Left, 4th Aug., 1887
Complete Accepted, 23rd Dec., 1887
I, ALEXANDER MELVILLE CLARK, of the firm of A. M and Wm. Clark, of 53,
Chancery Lane, in the County of Middlesex, Fellow of the Institute of Patent Agents,
do hereby declare the nature of this Invention a communication to me from abroad
by The Electrotechnische Fabrik Cannstatt, of Cannstatt, through their agents,
Wirth and Company, of Frankfort on the Main, both in Germany to be as follows:-
This invention relates to electric lighting installations in which a dynamo is
employed to charge accumulators which in turn supply the current to the lamps.
The invention consists on the one hand, of a self acting regulator which permits of
the accumulators being simultaneously charged and employed for lighting purposes,
and on the other hand of a self-acting device for switching on and off the connection
between the accumulators and the shunt-wound machine used for charging them.
If a dynamo, accumulators, and glow lamps be switched parallel, the tension alters
as is known in the accumulators and therefore also in the lamps according as the
former are being charged with a powerful or weak current, or even discharged.
A constant tension is maintained in the lamps by the following means:
The tension in the lamps (or also of the accumulators) is so chosen that the lowest
tension which is to be allowed in discharging the accumulators is equal to the tension
of the lamps.
Immediately the tension exceeds this measure (if it is not desired to alter the
number of the accumulators) a resistance must be switched in front of the lamps.
The object of this invention is to effect this automatically.
Referring to the accompanying drawing
A, A, figure 1 are coils in which iron cores B, are movable for the purpose of
making and breaking contacts C, D, whereby resistances are switched in and out of
the lamp circuit.
The coils are wound with fine wire and are placed directly on the accumulators so
hat the current passing through them, and also the position of the cores,
and the resistance switched in front of the lamps depend on the then tension of
he accumulators.

page_text: The self-acting switch used in charging the accumulators with the shunt-dynamo is
shewn in figures 2 and 3.
Upon one or both bobbins of an electro-magnet A, figures 2 and 3, are two kinds
of coils, the magnet current of the shunt-dynamo machine passes through the one and
the main current thereof flows through the other in the same direction.
The armature B in front of the pole pieces of the electro-magnet when attracted
makes a contact C, which is in fact, a contact for the main current.
The working of the apparatus is as follows:-Directly the machine starts, the
electro-magnet A is excited by the magnet current, whereupon the armature B is
attracted and makes the contact C, the main current circuit being thereby closed, the
machine current passes into the accumulators and simultaneously into the second coil
of the electro-magnet, where it strengthens the magnetism previously present, thus
benefitting the contact C.
If the machine be stopped, the magnetism of the electro-magnet sinks directly the
charging current falls to zero. Therefore on diminishing the velocity of the machine,
a return current would pass from the accumulators to the machine.
By means of a spiral spring D (or of a counter-weight E) the armature B, is
separated from the electro-magnet A, whereby the connection between the
accumulators and machine is broken.
Should, however, the connection fail to be instantly broken on the current ceasing,
the residual magnetism present in the electro-magnet will be so considerably weakened
by the action of the return current that the armature may easily be separated.
In figure 3, a solenoid spool a is wound as above described instead of an electro-
magnet as shown in figure 2, the iron core B, being drawn into the spool by the
action of the current, thus closing a contact C, which may be of platinum or mercury.
The working remains on the whole the same as in the above construction.
Dated this 24th day of November 1886.
A. MELVILLE CLARK.
By A. M. & Wm. Clark,
53, Chancery Lane, London,
Patent Agents.

page_text: I, ALEXANDER MELVILLE CLARK, of the firm of A. M. and Wm. Clark, of 53,
Chancery Lane, in the County of Middlesex, Fellow of the Institute of Patent Agents,
do hereby declare the nature of this Invention (a communication to me from abroad
by The Electrotechnische Fabrik Cannstatt of Cannstatt, through their agents Wirth
and Company, of Frankfort on the Main both in Germany, and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement :-
This invention relates to electric lighting installations in which a dynamo is
employed to charge accumulators which in turn supply the current to the lamps.
The invention consists on the one hand, of a self acting regulator which permits of
the accumulators being simultaneously charged and employed for lighting purposes,
and on the other hand of a self acting device for switching on and off the connection
between the accumulators and the shunt wound machine used for charging them.
If a dynamo, accumulators, and glow-lamps be arranged in multiple arc, the
terminal tension alters, as is known, in the accumulators and therefore also in the
lamps, according as the former are being charged with a powerful or weak current,
or being discharged.
If it be necessary to feed the lamps of an installation supplied by accumulators
while charging the latter, a difficulty has to be overcome, viz., that the charging
tension is much greater than the discharging tension so that without suitable means
of regulation, the lamps would burn too brightly in the one case and too dull in the
other.
A constant tension is maintained in the lamps by the following means;-The
tension in the lamps (or also of the accumulators) is so chosen that the lowest tension
which is to be allowed in discharging the accumulators is equal to the tension of
the lamps.
Immediately the tension exceeds this measure (if it is not desired to alter the
number of the accumulators) a resistance must be switched in front of the lamps.
The object of this invention is to provide automatic means of ensuring that the
tension at the lamps be no greater whilst charging the accumulators than the normal
discharging tension.
This is performed in the following manner, reference being had to the accompanying
drawings wherein figure 1 represents a diagram of the installation.
In a solenoid coil or coils A, are suspended an iron core or cores B which by their
motion within the coils press one or more of a series of contacts C C¹ C³ etc. against
spring contacts D D¹ D³ etc. according to the position of the core, thereby short
circuiting more or less, the resistances R, the contacts being so arranged as to be
closed and broken in succession by the upward and downward motion of the cores.
The spools A are wound with fine wire and are connected parallel to the
accumulator, and the resistances R are placed in front of the lamps L which are
intended for a normal discharging tension.
If the accumulators are not being charged, that is to say, if the automatic switch U
is opened automatically or otherwise, the iron core B will be raised to its highest
position by the counter balance, and the resistances R are then all short circuited, the
lamps being therefore connected directly to the accumulator terminals and burning
normally. Directly the dynamo M is set in motion and the switch U closed, the

page_text: tension in the accumulators rises, the cores B are drawn into the coils A and so switch
higher resistances R into circuit, the greater the accumulator tension becomes.
By choosing suitable resistances R, the tension of the lamps can in all cases be
rendered constant.
The self acting switch used in charging the accumulators with the shunt-dynamo is
shown in figure 2 and also in a modified form in figure 3. One or both bobbins of an
electro-magnet a figure 2 is or are wound with two kinds of coils, the magnet current
of the shunt dynamo machine passing through the one and the main current thereof
flowing through the other in the same direction. The armature B in front of the pole
pieces of the electro-magnet when attracted, closes a contact C which is in fact a
contact for the main current.
The working of the apparatus is as follows;-Directly the machine starts, the
electro-magnet a is excited by the magnet current whereupon the armature B is
attracted and makes the contact C; the main current circuit being thereby closed,
the machine current passes into the accumulators and simultaneously into the second
coil of the electro-magnet where it strengthens the magnetism previously present,
thus benefiting the contact (). If the machine be stopped, the magnetism of the
electro-magnet sinks directly the charging current falls to zero. Therefore, on
diminishing the velocity of the machine, a return current would pass from the
accumulators to the machine. By means of a spiral spring D (or its equivalent) the
armaturo B is separated from the electro-magnet a whereby the connection between
the accumulators and the machine is broken.
Should, however, the connection fail to be instantly broken on the current ceasing,
the residual magnetism present in the electro-magnet will be so considerably weakened
by the action of the return current, that the armature may easily be separated.
In the modification shown in figure 3, a solenoid spool a is wound as above
described, instead of an electro-magnet, as shown in figure 2, the iron core B being
drawn into the spool by the action of the current overcoming a counterweight E, and
thus closing a contact C which may be of platinum or mercury. The working
remains on the whole the same as in the above construction.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is-
1. A regulator for lighting with accumulators and dynamo, consisting of a fine
wire solenoid in parallel with the accumulators, and which, when the maximum safety
tension of the lamp current is exceeded, switches corresponding resistances into the
lamp circuit substantially as herein described.
2. For the purpose of the automatic switching off and on of the connection
between the shunt wound dynamo and the charged acumulator, I claim the arrange-
ment of an electro-magnet figure 2 or of a solenoid figure 3 with duplex coil of which
one is switched to the magnet current and the other to the main current which
directly influences the electro-magnet or solenoid, so that the latter by the action of
the machine with the help of the attracted armatures or cores closes the connection
between the machine and the accumulator to be charged, and breaks the same as soon
as the machine is stopped.