Improvements in Electrical Heating Apparatus.
Year: 1893

page_text: Date of Application, 14th Apr., 1893
Complete Specification Left, 31st Oct., 1893-Accepted, 16th Dec., 1893
PROVISIONAL SPECIFICATION.
Improvements in Electrical Heating Apparatus.
Sir DAVID LIONEL SALOMONS, Bart. of Broomhill, Tunbridge Wells,
Electrical Engineer, do hereby declare the nature of this invention to be as
follows:-
:―
The object of this invention is to provide an electric heater capable of raising
the temperature of a vessel and its contents, the same being applicable to, and a
removeable adjunct of, vessels or utensils of ordinary design.
I arrange that the said heater be constructed of such shape, form, and size, as
to readily pass through the orifice in the said vessel or chamber which is or may be
used for the introduction or withdrawal of the substance to be heated.
The electricity may be converted into heat either by direct resistance interposed
in the circuit or by any known indirect method.
I prefer to enclose the said direct or inductive resistance entirely within a
liquid-tight case.
manner.
may corrugate or otherwise extend the surface of the said case in any desired
prefer to construct this case of insulating material, or if of a conductor
of electricity, to efficiently electrically insulate the same from the current carrying
conductor.
I prefer to prolong in tubular form some part of the said case to beyond some
portion of the wall of the vessel or utensil, so as to form a protected orifice, for
the introduction of the current carrying conductor.
I prefer to attach the electric heater to the cover, lid, or other removeable
portion of the said heating vessel or utensil, preferably by some attachment upon
the before mentioned tubular prolongation of the water-tight containing case.
I prefer to provide the heater with some heat-insulating projections so placed
that if it be removed from the vessel or utensil, and placed upon some inflammable
substance, there may be no danger of the said substance becoming ignited.
For water-heaters, when connection between the liquid and the circuit would not
be objected to, I prefer to employ the liquid itself to wholly constitute or complete
the resistance circuit, so that the electric energy cannot be wasted when the heater
is not immersed in the liquid.
Where this device is not employed, I prefer to place a fusible wire in some
portion of the circuit, so that it may either break the circuit on any dangerous
access of current taking place or by reason of the general increase of heat which
would occur should a heater intended for use in liquids be accidentally connected
when not immersed in the same.
I may employ a float and contact device in connection with the same which shall
serve to complete the circuit when the level of the liquid is sufficiently high, and
to break the same when the heater is not properly covered. If it is desired that
one portion of the "containing case "shall be capable of being raised to a greater
heat than another portion, and that the said heat shall be less in another portion, I
may conveniently arrange the resistance in the form of a cone or pyramid, its
larger end being in the position requiring the greater heat, or I may use a
symmetrically shaped heating apparatus, the resistance or other losses being greater
in one position than in another, in the case of a resistance, the position where the
greater heat is required being wound with a finer gauge of wire.
Dated this 28th day of March 1893.

page_text: COMPLETE SPECIFICATION.
Improvements in Electrical Heating Apparatus.
Sir DAVID LIONEL SALOMONS, Bart. of Broomhill, Tunbridge Wells, Electrical
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 :-
The object of this invention is to provide an electric heater capable of raising
the temperature of a vessel and its contents, the same being applicable to, and a
removable adjunct of, vessels or utensils of ordinary design.
I arrange that the said heater be constructed of such shape, form, and size, as to
readily pass through the orifice in the said vessel or chamber which is or may be
used for the introduction or withdrawal of the substance to be heated.
The electricity may be converted into heat either by ohmic resistance interposed
directly in the circuit, or by any known indirect method.
I prefer to enclose the said direct or inductive resistance entirely within a
liquid-tight case.
I may corrugate or otherwise extend the surface of the said case in any desired
manner. I prefer to construct this case of electricity insulating material, or should
it be constructed of a conductor of electricity, to efficiently electrically insulate the
same from the current carrying conductor.
I prefer to prolong in tubular form some part of the said resistance case to a
distance sufficient to reach beyond some portion of the wall of the vessel or utensil
'containing the substance to be heated, in which it is placed, the prolongation forming
a protected orifice for the introduction of the current carrying conductor.
I prefer to attach the electric heater to the cover, lid, or other removable portion
of the said heating vessel or utensil preferably by some attachment upon the before
mentioned tubular prolongation of the water-tight containing case.
I prefer to provide the heater with some heat-insulating projections, so placed
that if it be removed from the vessel or utensil, and placed upon some inflammable
substance, there may be no danger of the said substance becoming ignited.
For water heaters, when connection between the liquid and the circuit would not
be objected to, I prefer to employ the liquid itself to wholly constitute or to
complete the resistance circuit, so that the electric energy cannot be wasted when
the heater is not immersed in the liquid. Where this device is not employed, I
prefer to place a fusible wire in some portion of the circuit, so that it may either
break the circuit on any dangerous access of current taking place, or by reason of
the general increase of heat which would occur should a heater intended for use in
liquids be accidentally connected when not immersed in the same.
may employ a float and contact device in connection with the same which shall
serve to complete the circuit when the level of the liquid is becomes too low,
& the resistance portion becomes exposed above liquid level, and to break the same
when the heater is not sufficiently covered, but it may be mentioned that this would
only be useful in the case of very small potentials or currents. If it is desired
that one portion of the "containing case" shall be capable of being raised to a
greater heat than another portion, and that the said heat shall be less in another
portion, I may conveniently arrange the resistance in the form of a cone or
pyramid, its larger end being in the position requiring the greater heat, or we may
use a symmetrically shaped heating apparatus, the resistance or other losses being
greater in one position than in another, in the case of a resistance, the position
where the greater heat is required being wound with a finer gauge of wire.
The drawings hereto appended illustrate various forms of apparatus embodying
the matters of my invention.
Fig. I is a sectional view of a water-boiler for attachment to an ordinary kettle-
lid. The case A and tube B are of tinned copper, the case being flat in design to

page_text: allow of a ready transference of the heat generated. D is a coil of asbestos-
covered German-silver wire connected to the leading-in flexible conductor about
two-thirds of the distance up the tube.
D', D¹ are hollow spherical feet of very thin copper.
E is a sliding knob and set-screw placed upon the tube B. To adapt this
heater to an ordinary kettle, it is only necessary to remove the knob from the
kettle-lid and then drill a hole through it sufficiently large to pass the tube
of the heater; place the heater in position in the kettle, having first removed
the sliding knob from the tube; solder, braze, or rivet this knob upon the
kettle-lid in place of the knob removed. Place the lid in position on the
kettle with the knob over the heater-tube and then having firmly fixed the set-
screw in the knob to the heater-tube the connecting conductor may be coupled to
the source of electric supply.
Fig. II represents in section a small form suitable for use in an ordinary
tumbler. It consists of A, a German-silver spiral wire covered with asbestos, in B,
a glass tube of spiral form together with C, à metallic silver plated guard, and D,
a porcelain cover.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:
1. In an electrical heating apparatus, the arrangement together of the usual
constituent parts in such a form and fashion that it may be readily introduced into
a vessel of ordinary design, substantially as described.
2. The combination of an electric heating apparatus and the lid, cover, or other
removable closing portion of an ordinary vessel or utensil.
3. The combination of an electric heating apparatus and an attachment for the
purpose of allowing its ready connection to the lid, cover, or other removable
closing portion of an ordinary vessel or utensil.
4. The combination of a removable electric heater and attached heat-insulating
feet, substantially as, and for the purpose described.
Dated this 30th day of October 1893.
DAVID LIONEL SALO
ONS.