IMPROVEMENTS IN APPARATUS FOR REGULATING ELECTRIC LIGHT
Year: 1878

page_text: LETTERS PATENT to Gustavus Palmer Harding, of No. 66, Avenue des Champs
Elysees, Paris, in the Republic of France, now residing at the Buckingham
Palace Hotel, in the City of Westminster, for the Invention of "IMPROVEMENTS
IN APPARATUS FOR REGULATING ELECTRIC LIGHT."
PROVISIONAL SPECIFICATION left by the said Gustavus Palmer Harding at
the Office of the Commissioners of Patents on the 12th October 1878.
GUSTAVUS PALMER HARDING, of No. 66, Avenue de Champs Elysees, Paris, in
the Republic of France, now rosiding at the Buckingham Palace Hotel, in the
City of Westminster. "IMPROVEMENTS IN APPARATUS FOR REGULATING. ELECTRIC
LIGHT."
This Invention has for its object improvements in obtaining electric light. A
large proportion of the cost of electric lighting is attributable to the "burner" or
parts in immediate connection with the exhibition of the light. Whether simple
electrodes of carbon or "the olectric candle" be employed the material is rapidly
dissipated by the intense heat of the electric arc, which also renders it impracticable
to employ burners which otherwise might be very conveniently used, as for
example platinum or other metallic conductors heated by the passage of the electric
current.
According to this Invention the heat at the burner is moderated by the appli-
cation of a regulator, which diverts a portion of the current when the heat tends to
rise unduly. This may be effected by a metallic wire so arranged that when
elongated by the heat to a certain extent (which can be adjusted as may be required)
it completes a shunt on the circuit, which carries a portion of the current away from
the burner.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Gustavus Palmer Harding in the Great Seal Patent Office on the
12th April 1879.
GUSTAVUS PALMER HARDING, of No. 66, Avenue de Champs Elysees, Paris, in
the Republic of France, now residing at the Buckingham Palace Hotel, in the City
of Westminster. "IMPROVEMENTS IN APPARATUS FOR REGULATING ELECTRIC
LIGHT."
This Invention has for its object improvements in apparatus for regulating electric
light. A large proportion of the cost of electric lighting is attributable to the
"burner" or parts in immediate connection with the exhibition of the light.
Whether simple electrodes of carbon or "the electric candle" be employed the
material is rapidly dissipated by the intense heat of the electric arc, which also
renders it impracticable to employ burners which otherwise might be very con-
veniently used, as for example platinum or other metallic conductors heated by the
passage of the electric current.
According to this Invention the heat at the burner is moderated by the appli-
cation of a regulator, which diverts a portion of the current when the heat tends to
rise unduly. This may be effected by a metallic wire so arranged that when
clongated by the heat to a certain extent (which can be adjusted as may be required)
it completes a shunt on the circuit, which carries a portion of the current away from
the burner.
In order that my said Invention may be most fully understood and readily
carried into effect. I will proceed to describe the Drawings hereunto annexed
Figure 1 shows the regulator, and Figure 2 indicates the arrangement in circuit.
a is a thin wire, by preference of silver, and b is a platinum or other spiral, which
being kept intensely heated by the electric current is the source of light. The
arrangement is such, as the Drawing indicates, that the same current which heats b
must pass through a. The wire a offers much less resistance to the current than
the light-emitting spiral b, and consequently is heated in a lesser degree, but its
temperature and that of the spiral 6 or "burner" will vary simultaneously.
The wire a, as is seen in Figure 1, is fixed at one end, and at the other is con-
nected with a lever c, to which a coiled spring is attached in such manner as to hold
the wire a slightly strained. d is an adjustable screw, the end of which is set in
proximately to a platinum plate upon the lever c. The expansion of the wire a by
heat causes contact between c and d when any desired temperature is reached, and
then a portion of the current is diverted by the shunt, and where a number of
lamps are included in the same circuit it passes on to the next lamp without
traversing the burner 6 corresponding to the regulator by which contact at c, d, has
been made. Any desired amount of resistance may be introduced in the shunt to
moderate to any extent desired the action of the regulator.
The arrangement at the burner may be varied. Thus in place of employing the
heated wire b to emit light directly I may cause it to heat a casing of lime or like
material with which it is enveloped, as is described in my Provisional Specification,
No. 783, in the year 1878, or I may cause an electric arc to be formed within a
cavity formed in a piece of lime, which being thus heated forms the burner of the
lamp, and produces a more regular and softer light than that of the arc from carbon
points or electrodes alone; or the lime, &c., may be so arranged that some portions
be carried on the electrodes by the action of the current, which becoming incan-
descent produce a similar result.
I also find it an advantage to introduce into the arc a small quantity of lime or
similar material, as by it I obtain greater regularity and softness in the light, and

page_text: greater duration in the carbon electrodes. This supply can be given by the action
of an expanding and contracting wire, or by an arrangement similar in principle to
that described with an electro-magnet. If the principle employed be that of the
expansion or contraction of a wire, I attach to the said wire one or more pieces of
lime or earthy material, which are fed in between the carbon points forming the
electric arc, and withdrawn as may be required by the contraction or the expansion
of the wire, which contraction or expansion is itself regulated by the greater or less
current in the electrodes, or the action may be reversed.
In place of arranging a number of lamps in continuous circuit they may be
arranged in parallel circuit, and in this case an electro-magnetic regulator may be
employed. Figure 3 illustrates a suitable arrangement.
a and b represent respec-
tively the flow and the return wires, on which a number of lamps may be arranged,
each as the Drawing indicates. c is the spiral or "burner," intensely heated by the
passage of the current. The same current also passes through the coils of the
electro-magnet d, causing it to attract its armature e. f is a spring holding off
the armature, but which yields when the attraction attains a certain force. ad-
justible by a screw which moves the magnet to or from the armature, or by varying
the tension of the spring f. When the armature approaches the magnet the circuit
is for the moment broken, the arm e¹ by which the armaturo is suspended and the
screw stop against which it reposes forming part of the burner circuit; or in place
of breaking the burner circuit increased resistance may be introduced into it by
establishing a connection through the resistance between the fulcrum of the arm e¹
and the stop g; or in the movement of the arm e¹ it may be caused to pass from
one contact to another, and so to introduce more and more resistance as it approaches
nearer and nearer to the magnet; or two or more electro-magnets may be used with
armatures held off by springs of different tension, and each armature as it leaves its
contact bringing an increase of resistance into the circuit.
Having thus described the nature of my said Invention, and the manner of
performing the sanie, I would have it understood that I claim the combination
with electric burners of apparatus which when the heat at any burner tends to rise
unduly diverts from it a portion of the current, substantially as described.
In witness whereof, I, the said Gustavus Palmer Harding, have hereunto set
my hand and seal, this Tenth day of April, in the year of our Lord One
thousand eight hundred and seventy-nine.
G. P. HARDING. (L.S.)